# Host availability alert **URL:** \ **Category:** Alerting\ **Tags:** management-zones, alerting-profile, hosts-classic\ **Created:** [January 2, 2026, 8:45am UTC](https://community.dynatrace.com/t/host-availability-alert/54521 "2026-01-02T08:45:18Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Adi\_10](https://avatars.discourse-cdn.com/v4/letter/a/ce7236/32.png) [@Adi\_10](https://community.dynatrace.com/u/Adi_10)\ **Post date:** [January 2, 2026, 8:45am UTC](https://community.dynatrace.com/t/host-availability-alert/54521/1 "2026-01-02T08:45:18Z")
Hello Team, we have some host running on our tenanat - some host are turned of and turned on automatically due to patching, manual task etc. We need a alert to be created when the host in my management zone are turned on. If host is turned of or shutdown - its not matter to us, but if our host turns on we need an alert for 1 specific MZ. ---
**Author:** ![Adi\_10](https://avatars.discourse-cdn.com/v4/letter/a/ce7236/32.png) [@Adi\_10](https://community.dynatrace.com/u/Adi_10)\ **Post date:** [January 2, 2026, 9:01am UTC](https://community.dynatrace.com/t/host-availability-alert/54521/2 "2026-01-02T09:01:09Z")
is this okay to use below built in metrics for this ? ![Adi_10_0-1767344453309.png](https://global.discourse-cdn.com/dynatrace/original/2X/7/788a447e13381c37df0035d8e55a31415c640347.png) ---
**Author:** ![Julius\_Loman](https://dub1.discourse-cdn.com/dynatrace/user_avatar/community.dynatrace.com/julius_loman/32/51_2.png) [@Julius\_Loman](https://community.dynatrace.com/u/Julius_Loman)\ **Post date:** [January 2, 2026, 9:33am UTC](https://community.dynatrace.com/t/host-availability-alert/54521/3 "2026-01-02T09:33:23Z")
Yes it is. You just need to play a little bit with the metric selector and add a delta transformation so you can easily create a metric event when hosť is turned on. ---
**Author:** ![Adi\_10](https://avatars.discourse-cdn.com/v4/letter/a/ce7236/32.png) [@Adi\_10](https://community.dynatrace.com/u/Adi_10)\ **Post date:** [January 2, 2026, 9:43am UTC](https://community.dynatrace.com/t/host-availability-alert/54521/4 "2026-01-02T09:43:48Z")
I have added a host tag filter and split by host , now the count is 1 and host number at x axis is four. If we have created a metric event for this we need to add static threshold to 1 if the limit ? I am confused here what to select as after selecting alert on missing data i am getting threshold number raised from 1 to 10 metric selector - builtin:host.availability.state:filter(and(or(in(“dt.entity.host”,entitySelector(“type(host),tag(~“code:A1233”~)”))),or(eq(“availability.state”,up)))):splitBy(“dt.entity.host”):sort(value(auto,descending)):limit(20)   - ![Adi_10_0-1767347013393.png](https://global.discourse-cdn.com/dynatrace/original/3X/b/1/b1775cb6dc91cd604aececa0a3809ffb31e36b57.png) I am bit confused here what to do next ? ---
**Author:** ![Julius\_Loman](https://dub1.discourse-cdn.com/dynatrace/user_avatar/community.dynatrace.com/julius_loman/32/51_2.png) [@Julius\_Loman](https://community.dynatrace.com/u/Julius_Loman)\ **Post date:** [January 2, 2026, 12:04pm UTC](https://community.dynatrace.com/t/host-availability-alert/54521/5 "2026-01-02T12:04:58Z")
Actually, there are multiple options: - Use builtin:host.uptime - the host uptime metric and alert when uptime is below certain time. (most simple solution - but does not distinguish between reboots and OneAgents offline) - Use builtin:host.availability:splitBy(“dt.entity.host”):delta metric selector and alert if value is non-zero. The delta transformation helps to filter only the spikes when the host (OneAgent) comes online. - Use the builtin:host.availability.state:filter(and(or(eq(“availability.state”,up)))):splitBy(“dt.entity.host”):default(0,always):delta  to filter just for availability up states. default transformation adds zero and delta transformation assures the final metric will show only the state changes. - this metric however does not work for paas agents (only for full stack agents). ---
**Author:** ![Adi\_10](https://avatars.discourse-cdn.com/v4/letter/a/ce7236/32.png) [@Adi\_10](https://community.dynatrace.com/u/Adi_10)\ **Post date:** [January 8, 2026, 8:01am UTC](https://community.dynatrace.com/t/host-availability-alert/54521/6 "2026-01-08T08:01:49Z")
Used the builtin:host.availability.state:filter(and(or(eq(“availability.state”,up)))):splitBy(“dt.entity.host”):default(0,always):delta It’s perfect metric for my host using some new entities tag - I have added this on my production env tested and verified. thank you [@JuliusLoman](https://community.dynatrace.com/user/58579)